Subject: [net-next-2.6 PATCH 09/10] tg3: remove use of skb_dma_map/unmap

From: Jeff Kirsher <[email-masked]>
Date: Wed, 02 Dec 2009 18:48:38 -0800

From: Alexander Duyck <[email-masked]>

Due to the fact that skb_dma_map/unmap do not work correctly when a HW
IOMMU is enabled it has been recommended to go about removing the calls
from the network device drivers.

Signed-off-by: Alexander Duyck <[email-masked]>
Signed-off-by: Jeff Kirsher <[email-masked]>
CC: Matt Carlson <[email-masked]>
CC: Michael Chan <[email-masked]>
---

 drivers/net/tg3.c |  173 ++++++++++++++++++++++++++++++++++++++++-------------
 drivers/net/tg3.h |    6 --
 2 files changed, 132 insertions(+), 47 deletions(-)

diff --git a/drivers/net/tg3.c b/drivers/net/tg3.c
index 6e6db95..302ea0b 100644
--- a/drivers/net/tg3.c
+++ b/drivers/net/tg3.c
@@ -4357,7 +4357,7 @@ static void tg3_tx(struct tg3_napi *tnapi)
 	txq = netdev_get_tx_queue(tp->dev, index);
 
 	while (sw_idx != hw_idx) {
-		struct tx_ring_info *ri = &tnapi->tx_buffers[sw_idx];
+		struct ring_info *ri = &tnapi->tx_buffers[sw_idx];
 		struct sk_buff *skb = ri->skb;
 		int i, tx_bug = 0;
 
@@ -4366,7 +4366,10 @@ static void tg3_tx(struct tg3_napi *tnapi)
 			return;
 		}
 
-		skb_dma_unmap(&tp->pdev->dev, skb, DMA_TO_DEVICE);
+		pci_unmap_single(tp->pdev,
+				 pci_unmap_addr(ri, mapping),
+				 skb_headlen(skb),
+				 PCI_DMA_TODEVICE);
 
 		ri->skb = NULL;
 
@@ -4376,6 +4379,11 @@ static void tg3_tx(struct tg3_napi *tnapi)
 			ri = &tnapi->tx_buffers[sw_idx];
 			if (unlikely(ri->skb != NULL || sw_idx == hw_idx))
 				tx_bug = 1;
+
+			pci_unmap_page(tp->pdev,
+				       pci_unmap_addr(ri, mapping),
+				       skb_shinfo(skb)->frags[i].size,
+				       PCI_DMA_TODEVICE);
 			sw_idx = NEXT_TX(sw_idx);
 		}
 
@@ -5334,17 +5342,21 @@ static int tigon3_dma_hwbug_workaround(struct tg3_napi *tnapi,
 	} else {
 		/* New SKB is guaranteed to be linear. */
 		entry = *start;
-		ret = skb_dma_map(&tp->pdev->dev, new_skb, DMA_TO_DEVICE);
-		new_addr = skb_shinfo(new_skb)->dma_head;
+		new_addr = pci_map_single(tp->pdev, new_skb->data, new_skb->len,
+					  PCI_DMA_TODEVICE);
+		/* Make sure the mapping succeeded */
+		if (pci_dma_mapping_error(tp->pdev, new_addr)) {
+			ret = -1;
+			dev_kfree_skb(new_skb);
+			new_skb = NULL;
 
 		/* Make sure new skb does not cross any 4G boundaries.
 		 * Drop the packet if it does.
 		 */
-		if (ret || ((tp->tg3_flags3 & TG3_FLG3_4G_DMA_BNDRY_BUG) &&
-			    tg3_4g_overflow_test(new_addr, new_skb->len))) {
-			if (!ret)
-				skb_dma_unmap(&tp->pdev->dev, new_skb,
-					      DMA_TO_DEVICE);
+		} else if ((tp->tg3_flags3 & TG3_FLG3_4G_DMA_BNDRY_BUG) &&
+			    tg3_4g_overflow_test(new_addr, new_skb->len)) {
+			pci_unmap_single(tp->pdev, new_addr, new_skb->len,
+					 PCI_DMA_TODEVICE);
 			ret = -1;
 			dev_kfree_skb(new_skb);
 			new_skb = NULL;
@@ -5358,15 +5370,28 @@ static int tigon3_dma_hwbug_workaround(struct tg3_napi *tnapi,
 	/* Now clean up the sw ring entries. */
 	i = 0;
 	while (entry != last_plus_one) {
+		int len;
+
 		if (i == 0)
-			tnapi->tx_buffers[entry].skb = new_skb;
+			len = skb_headlen(skb);
 		else
+			len = skb_shinfo(skb)->frags[i-1].size;
+
+		pci_unmap_single(tp->pdev,
+				 pci_unmap_addr(&tnapi->tx_buffers[entry],
+						mapping),
+				 len, PCI_DMA_TODEVICE);
+		if (i == 0) {
+			tnapi->tx_buffers[entry].skb = new_skb;
+			pci_unmap_addr_set(&tnapi->tx_buffers[entry], mapping,
+					   new_addr);
+		} else {
 			tnapi->tx_buffers[entry].skb = NULL;
+		}
 		entry = NEXT_TX(entry);
 		i++;
 	}
 
-	skb_dma_unmap(&tp->pdev->dev, skb, DMA_TO_DEVICE);
 	dev_kfree_skb(skb);
 
 	return ret;
@@ -5403,10 +5428,11 @@ static netdev_tx_t tg3_start_xmit(struct sk_buff *skb,
 {
 	struct tg3 *tp = netdev_priv(dev);
 	u32 len, entry, base_flags, mss;
-	struct skb_shared_info *sp;
 	dma_addr_t mapping;
 	struct tg3_napi *tnapi;
 	struct netdev_queue *txq;
+	unsigned int i, last;
+
 
 	txq = netdev_get_tx_queue(dev, skb_get_queue_mapping(skb));
 	tnapi = &tp->napi[skb_get_queue_mapping(skb)];
@@ -5477,18 +5503,17 @@ static netdev_tx_t tg3_start_xmit(struct sk_buff *skb,
 			       (vlan_tx_tag_get(skb) << 16));
 #endif
 
-	if (skb_dma_map(&tp->pdev->dev, skb, DMA_TO_DEVICE)) {
+	len = skb_headlen(skb);
+
+	/* Queue skb data, a.k.a. the main skb fragment. */
+	mapping = pci_map_single(tp->pdev, skb->data, len, PCI_DMA_TODEVICE);
+	if (pci_dma_mapping_error(tp->pdev, mapping)) {
 		dev_kfree_skb(skb);
 		goto out_unlock;
 	}
 
-	sp = skb_shinfo(skb);
-
-	mapping = sp->dma_head;
-
 	tnapi->tx_buffers[entry].skb = skb;
-
-	len = skb_headlen(skb);
+	pci_unmap_addr_set(&tnapi->tx_buffers[entry], mapping, mapping);
 
 	if (GET_ASIC_REV(tp->pci_chip_rev_id) == ASIC_REV_5717 &&
 	    !mss && skb->len > ETH_DATA_LEN)
@@ -5501,15 +5526,21 @@ static netdev_tx_t tg3_start_xmit(struct sk_buff *skb,
 
 	/* Now loop through additional data fragments, and queue them. */
 	if (skb_shinfo(skb)->nr_frags > 0) {
-		unsigned int i, last;
-
 		last = skb_shinfo(skb)->nr_frags - 1;
 		for (i = 0; i <= last; i++) {
 			skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
 
 			len = frag->size;
-			mapping = sp->dma_maps[i];
+			mapping = pci_map_page(tp->pdev,
+					       frag->page,
+					       frag->page_offset,
+					       len, PCI_DMA_TODEVICE);
+			if (pci_dma_mapping_error(tp->pdev, mapping))
+				goto dma_error;
+
 			tnapi->tx_buffers[entry].skb = NULL;
+			pci_unmap_addr_set(&tnapi->tx_buffers[entry], mapping,
+					   mapping);
 
 			tg3_set_txd(tnapi, entry, mapping, len,
 				    base_flags, (i == last) | (mss << 1));
@@ -5532,6 +5563,27 @@ out_unlock:
 	mmiowb();
 
 	return NETDEV_TX_OK;
+
+dma_error:
+	last = i;
+	entry = tnapi->tx_prod;
+	tnapi->tx_buffers[entry].skb = NULL;
+	pci_unmap_single(tp->pdev,
+			 pci_unmap_addr(&tnapi->tx_buffers[entry], mapping),
+			 skb_headlen(skb),
+			 PCI_DMA_TODEVICE);
+	for (i = 0; i <= last; i++) {
+		skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
+		entry = NEXT_TX(entry);
+
+		pci_unmap_page(tp->pdev,
+			       pci_unmap_addr(&tnapi->tx_buffers[entry],
+					      mapping),
+			       frag->size, PCI_DMA_TODEVICE);
+	}
+
+	dev_kfree_skb(skb);
+	return NETDEV_TX_OK;
 }
 
 static netdev_tx_t tg3_start_xmit_dma_bug(struct sk_buff *,
@@ -5579,11 +5631,12 @@ static netdev_tx_t tg3_start_xmit_dma_bug(struct sk_buff *skb,
 {
 	struct tg3 *tp = netdev_priv(dev);
 	u32 len, entry, base_flags, mss;
-	struct skb_shared_info *sp;
 	int would_hit_hwbug;
 	dma_addr_t mapping;
 	struct tg3_napi *tnapi;
 	struct netdev_queue *txq;
+	unsigned int i, last;
+
 
 	txq = netdev_get_tx_queue(dev, skb_get_queue_mapping(skb));
 	tnapi = &tp->napi[skb_get_queue_mapping(skb)];
@@ -5678,21 +5731,19 @@ static netdev_tx_t tg3_start_xmit_dma_bug(struct sk_buff *skb,
 	    !mss && skb->len > ETH_DATA_LEN)
 		base_flags |= TXD_FLAG_JMB_PKT;
 
-	if (skb_dma_map(&tp->pdev->dev, skb, DMA_TO_DEVICE)) {
+	len = skb_headlen(skb);
+
+	mapping = pci_map_single(tp->pdev, skb->data, len, PCI_DMA_TODEVICE);
+	if (pci_dma_mapping_error(tp->pdev, mapping)) {
 		dev_kfree_skb(skb);
 		goto out_unlock;
 	}
 
-	sp = skb_shinfo(skb);
-
-	mapping = sp->dma_head;
-
 	tnapi->tx_buffers[entry].skb = skb;
+	pci_unmap_addr_set(&tnapi->tx_buffers[entry], mapping, mapping);
 
 	would_hit_hwbug = 0;
 
-	len = skb_headlen(skb);
-
 	if ((tp->tg3_flags3 & TG3_FLG3_SHORT_DMA_BUG) && len <= 8)
 		would_hit_hwbug = 1;
 
@@ -5714,16 +5765,21 @@ static netdev_tx_t tg3_start_xmit_dma_bug(struct sk_buff *skb,
 
 	/* Now loop through additional data fragments, and queue them. */
 	if (skb_shinfo(skb)->nr_frags > 0) {
-		unsigned int i, last;
-
 		last = skb_shinfo(skb)->nr_frags - 1;
 		for (i = 0; i <= last; i++) {
 			skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
 
 			len = frag->size;
-			mapping = sp->dma_maps[i];
+			mapping = pci_map_page(tp->pdev,
+					       frag->page,
+					       frag->page_offset,
+					       len, PCI_DMA_TODEVICE);
 
 			tnapi->tx_buffers[entry].skb = NULL;
+			pci_unmap_addr_set(&tnapi->tx_buffers[entry], mapping,
+					   mapping);
+			if (pci_dma_mapping_error(tp->pdev, mapping))
+				goto dma_error;
 
 			if ((tp->tg3_flags3 & TG3_FLG3_SHORT_DMA_BUG) &&
 			    len <= 8)
@@ -5779,6 +5835,27 @@ out_unlock:
 	mmiowb();
 
 	return NETDEV_TX_OK;
+
+dma_error:
+	last = i;
+	entry = tnapi->tx_prod;
+	tnapi->tx_buffers[entry].skb = NULL;
+	pci_unmap_single(tp->pdev,
+			 pci_unmap_addr(&tnapi->tx_buffers[entry], mapping),
+			 skb_headlen(skb),
+			 PCI_DMA_TODEVICE);
+	for (i = 0; i <= last; i++) {
+		skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
+		entry = NEXT_TX(entry);
+
+		pci_unmap_page(tp->pdev,
+			       pci_unmap_addr(&tnapi->tx_buffers[entry],
+					      mapping),
+			       frag->size, PCI_DMA_TODEVICE);
+	}
+
+	dev_kfree_skb(skb);
+	return NETDEV_TX_OK;
 }
 
 static inline void tg3_set_mtu(struct net_device *dev, struct tg3 *tp,
@@ -6046,8 +6123,9 @@ static void tg3_free_rings(struct tg3 *tp)
 			continue;
 
 		for (i = 0; i < TG3_TX_RING_SIZE; ) {
-			struct tx_ring_info *txp;
+			struct ring_info *txp;
 			struct sk_buff *skb;
+			unsigned int k;
 
 			txp = &tnapi->tx_buffers[i];
 			skb = txp->skb;
@@ -6057,11 +6135,22 @@ static void tg3_free_rings(struct tg3 *tp)
 				continue;
 			}
 
-			skb_dma_unmap(&tp->pdev->dev, skb, DMA_TO_DEVICE);
-
+			pci_unmap_single(tp->pdev,
+					 pci_unmap_addr(txp, mapping),
+					 skb_headlen(skb),
+					 PCI_DMA_TODEVICE);
 			txp->skb = NULL;
 
-			i += skb_shinfo(skb)->nr_frags + 1;
+			i++;
+
+			for (k = 0; k < skb_shinfo(skb)->nr_frags; k++) {
+				txp = &tnapi->tx_buffers[i & (TG3_TX_RING_SIZE - 1)];
+				pci_unmap_page(tp->pdev,
+					       pci_unmap_addr(txp, mapping),
+					       skb_shinfo(skb)->frags[k].size,
+					       PCI_DMA_TODEVICE);
+				i++;
+			}
 
 			dev_kfree_skb_any(skb);
 		}
@@ -6231,7 +6320,7 @@ static int tg3_alloc_consistent(struct tg3 *tp)
 
 		memset(tnapi->rx_rcb, 0, TG3_RX_RCB_RING_BYTES(tp));
 
-		tnapi->tx_buffers = kzalloc(sizeof(struct tx_ring_info) *
+		tnapi->tx_buffers = kzalloc(sizeof(struct ring_info) *
 					    TG3_TX_RING_SIZE, GFP_KERNEL);
 		if (!tnapi->tx_buffers)
 			goto err_out;
@@ -10637,7 +10726,8 @@ static int tg3_run_loopback(struct tg3 *tp, int loopback_mode)
 	for (i = 14; i < tx_len; i++)
 		tx_data[i] = (u8) (i & 0xff);
 
-	if (skb_dma_map(&tp->pdev->dev, skb, DMA_TO_DEVICE)) {
+	map = pci_map_single(tp->pdev, skb->data, tx_len, PCI_DMA_TODEVICE);
+	if (pci_dma_mapping_error(tp->pdev, map)) {
 		dev_kfree_skb(skb);
 		return -EIO;
 	}
@@ -10651,8 +10741,7 @@ static int tg3_run_loopback(struct tg3 *tp, int loopback_mode)
 
 	num_pkts = 0;
 
-	tg3_set_txd(tnapi, tnapi->tx_prod,
-		    skb_shinfo(skb)->dma_head, tx_len, 0, 1);
+	tg3_set_txd(tnapi, tnapi->tx_prod, map, tx_len, 0, 1);
 
 	tnapi->tx_prod++;
 	num_pkts++;
@@ -10676,7 +10765,7 @@ static int tg3_run_loopback(struct tg3 *tp, int loopback_mode)
 			break;
 	}
 
-	skb_dma_unmap(&tp->pdev->dev, skb, DMA_TO_DEVICE);
+	pci_unmap_single(tp->pdev, map, tx_len, PCI_DMA_TODEVICE);
 	dev_kfree_skb(skb);
 
 	if (tx_idx != tnapi->tx_prod)
diff --git a/drivers/net/tg3.h b/drivers/net/tg3.h
index 453a34f..8972523 100644
--- a/drivers/net/tg3.h
+++ b/drivers/net/tg3.h
@@ -2441,10 +2441,6 @@ struct ring_info {
 	DECLARE_PCI_UNMAP_ADDR(mapping)
 };
 
-struct tx_ring_info {
-	struct sk_buff			*skb;
-};
-
 struct tg3_config_info {
 	u32				flags;
 };
@@ -2608,7 +2604,7 @@ struct tg3_napi {
 
 	struct tg3_rx_buffer_desc	*rx_rcb;
 	struct tg3_tx_buffer_desc	*tx_ring;
-	struct tx_ring_info		*tx_buffers;
+	struct ring_info		*tx_buffers;
 
 	dma_addr_t			status_mapping;
 	dma_addr_t			rx_rcb_mapping;